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Biomedical subjects

B E García

Publications and source records attributed to B E García.

15 recordsLinked to original sources
PubMed1991

Number of beta-receptors in patients allergic to Dermatophagoides pteronyssinus.

This study was carried out on 96 atopic patients with monosensitization against Dermatophagoides pteronyssinus and 30 control individuals. The patients were divided into 3 subgroups: 27 asymptomatic patients, 27 patients who only presented nasal symptomatology, and 27 patients with marked bronchial symptomatology. Total serum IgE, antigen-specific histamine release, and the number of beta 2-adrenergic receptors in peripheral blood lymphocytes in all patients were determined. The control group presented the highest number of beta-receptors in comparison with the bronchial symptomatic and nasal symptomatic patients. However, asymptomatic patients presented numbers of beta-receptors similar to controls, with no significant differences between both groups. No significant correlation was found between beta-adrenergic receptors and levels of total serum IgE. On the other hand, correlation between beta-receptors and specific histamine release was detected only in symptomatic nasal patients. It can be postulated that the decrease in beta-receptors is a consequence, and not the cause, of atopy.

Adult↗
PubMed1991

Number of beta-receptors in rhinitic pollinic patients.

The study was carried out on venous blood from 67 patients with seasonal rhinoconjunctivitis caused by sensitization to grass pollen and 30 control individuals. Total IgE determination, antigen-specific histamine release test against two concentrations of Phleum pratense, and quantification of beta 2-adrenergic receptor numbers in lymphocyte membrane of peripheral blood were done on all patients. Those pollinic patients who were asymptomatic at the time of the study had 500.07 +/- 237.27 receptors/cell; no significant differences were established with the control group, with 541.53 +/- 123.63 receptors/cell. However, both the control group and asymptomatic patients had receptor numbers which were significantly higher than those of symptomatic pollinic patients, with 376.81 +/- 158.65 receptors/cell (p < 0.01 and p < 0.05, respectively). The average decrease in number of receptors in symptomatic pollinic patients was 30.42% in relation to controls and 24.65% in relation to asymptomatic patients. Within the subgroup of pollinic patients, studied both in and out of season, the number of beta 2-adrenergic receptors had an average decrease of 13.22% during pollination, with 363.7 receptors/cell. Once the pollination season was over, this figure increased to 419.1 receptors/cell, establishing significant differences with p < 0.025. The number of beta 2-adrenergic receptors did not correlate with total seric IgE figures or with antigen-specific histamine release. These data indicate that the decrease of these receptors does not constitute the causal factor of atopic diseases; it seems more likely to be a consequence of the same.

Adolescent↗
PubMed1991

Study of IgE-dependent basophil releasability in allergic patients.

For this study, venous blood from 160 patients with a diagnosis of asthma and/or rhinitis was used. Histamine release test (H.R.T.) with anti-IgE at 1/5 and 1/25 dilutions and with causal antigen in the case of atopic patients (144) was carried out on all patients. Basophils from atopic patients released more histamine than those from nonatopic patients (p < 0.001). Basophils of atopic patients released more histamine with 1/5 anti-IgE dilution (p < 0.01), while non-atopic patients did so with the 1/25 dilution (p < 0.05). On grouping atopic patients according to positive or negative results in Ag-specific histamine release, 14% of patients presented negative Ag-specific H.R.T. and 85.7% of the cases did not respond to anti-IgE stimulus; this was 12% of the total number of atopics. On the other hand, 17% of the patients studied did not show positive histamine release against anti-IgE and 70.6% of them had negative Ag-specific release. As for the effect of age on IgE-dependent histamine release, the group of patients who presented greater releasability corresponded to those older than 6 years of age. The discrepancies observed between the clinical history, skin tests, serum IgE and antigen-dependent histamine release in some patients could be related to the individual basophil ability to release histamine. Therefore, this basophil releasability evaluation has an important practical application in discerning false negatives in antigen-specific H.R.T.

Adolescent↗
PubMed1989

Results of the in vitro follow-up of immunotherapy.

With the advances made in allergological diagnosis, thanks to the application of various in vitro immunological techniques, we have also learnt more about the immunological modifications produced during the course of the immunotherapy. Among the techniques which will detect immunological changes is the histamine release test, which will show a decrease in antigen-specific histamine release. On the other hand, both total IgE and IgG4 are modified in the course of this immunotherapeutic treatment.

Follow-Up Studies↗
PubMedDate not supplied

Specific IgG subclasses in pollinosis.

We studied IgG subclasses in pollinosis in order to determine the possible immunopathological role of these antibodies, especially antigen-specific IgG4. The selection of pollinosic patients allowed us to observe the influence natural antigenic exposure exerts upon antibodies. On the other hand, we intended to study the possible modifications immunotherapy produces on IgG subclasses. For this purpose, we selected 266 patients who were classified into the following groups: Group I, 65 patients without immunotherapy, 35 of whom were studied during the pollen season and 30 outside the pollen season; Group II, 40 nonpollinosic patients with hypersensitization to Dermatophagoides pteronyssinus were taken as atopic controls; Group III, 161 pollinosic patients with from 3 to 42 months of immunotherapy. For every patient, IgG1, IgG2 and IgG3 against Phleum pratense were determined by means of ELAST (Leti), and IgG4 against the same allergen by means of the ELISA technique developed by us. Our results confirm, first, that untreated pollinosic patients present higher concentrations of IgG4 against Phleum than nonpollinosic patients, and second, that immunotherapy produces significant modifications in the production of antigen-specific IgG.

Antibody Specificity↗
PubMedDate not supplied

Effect of ketotifen on phosphodiesterase activity from asthmatic individuals.

It was demonstrated, in this study, that phosphodiesterase activity was elevated in asthmatic patients compared to healthy individuals. This may be reason why various authors found higher intracellular cAMP levels in healthy individuals than in asthmatic patients. We also demonstrated that the efficacy of ketotifen in inhibiting antigen-specific histamine release is due to the potent inhibitor effect of ketotifen on cellular phosphodiesterase activity which then allowed intracellular cAMP accumulation, and as a consequence prevented mediators release.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

Decrease of beta-receptors after the antigen-specific bronchial provocation test in bronchial asthma.

Airway hyperreactivity to different stimuli is a characteristic feature of bronchial asthma. The beta-adrenergic theory, as proposed by Szentivanyi in 1968, tried to explain with beta-adrenergic dysfunction, the cause not only of bronchial hyperreactivity but of all atopic diseases. In a previous work, we found that asymptomatic asthmatic patients presented a number of beta-receptors similar to that of a normal control group, while symptomatic asthmatic patients presented a significantly decreased number when compared to both groups (40% decrease). In view of these results, we proposed to study the possible changes in the number of beta-receptors in asymptomatic asthmatic patients after a bronchial provocation test. Fifteen patients, diagnosed of bronchial asthma and sensitive to the house dust mite, D. pteronyssinus, were studied. All were free of medication and asymptomatic at least 90 days before the study. A test of specific bronchial provocation was performed on 10 patients, determining the number of beta-receptors in basal conditions, after 30 minutes and 24 hours. The other five patients underwent an unspecific provocation test with methacholine, with determination of the beta-receptor number at basal conditions, and 24 hours later. Only a significant decrease (30.4%) was found in the beta-receptor numbers, 24 hours after specific bronchial provocation with p less than 0.025 with the Student test for paired data. With regards the beta-adrenergic theory of atopy, in our opinion our results show that the detected decrease of beta-receptors would be the consequence and not the cause of atopic diseases.

Allergens↗
PubMedDate not supplied

Value of IgG4 antibodies against foods in atopic dermatitis.

Various authors have linked IgG4 antibodies to biological activities that are apparently contradictory in different studies. On one hand, it has been confirmed that during immunotherapy with inhalant and Hymenoptera venom antigens, an increase is produced in specific IgG4 levels. On the other hand, it has been suggested that these antibodies can intervene in hypersensitivity reactions, basically when these are directed against food antigens. We studied IgG4 levels against milk and egg fractions in patients with atopic dermatitis (AD) (n = 23), and in healthy individuals (n = 20). Patients with AD had significantly much higher IgG4 levels against egg white (24.16 micrograms/ml), egg yolk (9.96 micrograms/ml) and beta-lactoglobulin (10 micrograms/ml) than those found in healthy individuals (6.75, 3.12, 3.35 micrograms/ml, respectively), with no significant differences for alpha-lactalbumin and casein. Patients with AD without hypersensitivity to egg and milk, at the moment of the study, also had significantly higher levels than those of control individuals, against egg white (27.11 micrograms/ml), egg yolk (12 micrograms/ml) and beta-lactoglobulin (11.72 micrograms/ml). There were no differences in IgG4 levels against alpha-lactalbumin, beta-lactoglobulin and casein, when comparing patients with AD and hypersensitivity to milk, and patients with AD without present hypersensitivity to milk. We concluded that patients with AD presented high IgG4 levels against egg and milk fractions, in relation to the healthy population, and that the fraction of milk with the highest antigenic potency was beta-lactoglobulin.

Adolescent↗
PubMedDate not supplied

Late asthmatic reaction in a hairdresser, due to the inhalation of ammonium persulphate salts.

Persulphate salts are among the various chemical substances that can cause occupational diseases in hairdressers. We present the case of a 21 year-old female who worked in a hairdressing salon for five and a half years. Five years prior to consultation, she presented with rhinitic symptoms and wheezing dyspnea which were related with her working environment. The routine laboratory examinations carried out on the patient were found to be normal. Among the various allergic exams performed there was an elevated total IgE. The provocation test with histamine was positive at the concentration of 10 mg/ml, demonstrating mild bronchial hyperreactivity. The test of bronchial exposure to ammonium persulphate was positive with bronchospasm 3-4 hours after this test. With a prior inhalation of betamethasone we were able to block this reaction, but with disodium cromoglycate we were able to block it only partially. We conclude that the patient presented with late onset bronchial asthma due to sensitivity to ammonium persulphate. It has to be pointed out that this patient was a rare case as generally persulphate salts choose to invade and affect the skin. The rarity of this pathology is reflected by the scarce bibliography on this subject.

Adult↗
PubMedDate not supplied

Food allergy to Helix terrestre (snail).

Among the rare foods capable of producing food allergies is the snail (Helix terrestre). The snail is a delicacy eaten in Spain, France and Portugal. This study presents the findings of an allergic study of 10 patients with this infrequent food allergy during the past 10 years. The shock organ in the majority (80%) of these patients was the bronchial tree. Six of them did not have any digestive or skin symptoms which are usually seen in cases of food allergy. All patients manifested the symptomatology after ingestion of Helix terrestre. Two also had reactions after eating Patella vulgata (limpet). The snail and the limpet are within the phylogenetic line of molluscs, i.e. of gastropods. All patients tolerated the ingestion of cephalopods and bivalves which belong to two other phylogenetic lines. Skin tests to seafoods (squids, prawns, lobsters and clams) were negative for all patients. This suggests that the sensitizing antigen is probably a protein found only in gastropod molluscs. Skin tests along with the histamine release test were valid diagnostic methods for this food allergy. The limited bibliography on this subject is probably due to the fact that the consumption of snails as well as limpets is limited to specific geographical areas.

Adolescent↗
PubMedDate not supplied

The value of total IgE determination in mite allergy.

Our aim was to study the behaviour of patients with perennial respiratory allergy in relation to total IgE production. We chose patients allergic to house dust mite Dermatophagoides pteronyssinus, because this is the most representative perennial antigen. The total IgE in a wide group of patients was evaluated in relation to diagnosis, clinical activity, and seasonal changes. We also studied the possible changes in relation to immunotherapy. The total IgE was measured through enzyme immunoassay (Kallestad). To compare the results, a Student's test for independent data was performed and a statistically significant difference (p less than 0.001) in the IgE levels was found between the rhinitis and asthma groups with or without associated rhinitis. We did not obtain any differences between the groups in relation to clinical activity or seasonal changes. In relation to the possible changes in IgE levels according to the duration of immunotherapy, we observed a mild elevation before 7 months and between 13 and 24 months of treatment, without any significant differences with respect to basal levels. The determination of total IgE seems to us a valid and necessary test to complete the diagnosis of the existence of a cytotropic hypersensitivity mechanism in respiratory pathology. However, it seems to be less sensitive because it does not detect changes with respect to clinical activity, seasonal changes or duration of immunotherapy when dealing with perennial antigens.

Animals↗
PubMedDate not supplied

A rare case of food allergy: monosensitivity to kiwi (Actinidia chinensis).

We present a case of hypersensitivity to kiwi in a 26 year-old patient with no previous atopic history. The first reaction episode occurred a few minutes after kiwi ingestion, presenting with a localized pruritic reaction. This symptomatology repeated itself a few months later, again immediately after eating kiwi and was accompanied by dysphagia, vomiting and urticaria. In the complementary laboratory analyses a total IgE of 187 IU/ml was appreciated. The skin test to inhalant and food antigens were negative, while the kiwi extract produced a + + + + reaction. The histamine release test was positive (20%). Specific IgE levels (Kallestad) demonstrated results of 0.35 AEU/ml (class I). Specific IgG4 levels were normal and the hemagglutination test was negative. With the above results, we concluded that we were dealing with a case of monosensitivity to kiwi which was probably IgE mediated.

Adult↗
PubMedDate not supplied

Effect of ketotifen on adenyl cyclase activity in asthmatic patients.

Employing peripheral blood leucocytes as the model of the study, we proved how ketotifen blocks the inhibiting effect that the antigen induces over the adenyl cyclase activity in asthmatic individuals with sensitization to Dermatophagoides pteronyssinus. The strength of the Ketotifen effect is comparable to that produced on beta-receptor stimulation by isoproterenol. On the other hand, we found that within the same age range, the activity of adenyl cyclase in asthmatic individuals is comparable to healthy individuals, although the response is not the same to isoporoterenol which is greater in the control group. This is probably due to the diminished number of beta-receptors in asthmatic individuals as compared to healthy ones.

Adenylyl Cyclases↗
PubMedDate not supplied

Effect of immunotherapy on antigen-specific IgG4 in asthmatics sensitive to D. pteronyssinus.

The aim of this paper is to study the optical density (O.D.) values, correlated with an ELISA system to determine specific IgG4 levels against D. pteronyssinus in the serum of 20 control subjects, 35 asthmatic patients without previous immunotherapy (I.T.) and 77 patients who had variable periods of I.T. The group of non-treated patients showed specific IgG4 levels which were significantly higher than those of the control group (p less than 0.05). In this group of patients, 31.43% of the cases showed levels superior to the control group. All treated patient groups showed specific IgG4 levels which were significantly higher than those of the control group and than those of the non-treated patients, with various levels of significance (see Table IV). Of the asthmatic patients with I.T. as a whole group, 59.74% showed O.D. levels superior to the control group. The highest level of specific IgG4 was found in the patient group with the longest time of I.T. There was no significant correlation between the specific IgG4 levels with the different immunologic parameters (cutaneous reactivity, HRT, total and specific IgE). As for the clinical picture, there were no significant differences in comparing active with inactive patients during the period of study. There were no statistically significant differences in the levels observed between patients with a good clinical course and those who did not respond favourably, although all the groups of patients with a good response had higher specific IgG4 levels. This way, these antibodies may play the role of a blocking agent.

Adolescent↗